docs: def kxtrct(keywd, terms, nterms, instring, termlen=_default_len_out, stringlen=_default_len_out, substrlen=_default_len_out):
      """
      Locate a keyword in a string and extract the substring from
      the beginning of the first word following the keyword to the
      beginning of the first subsequent recognized terminator of a list.
  
      http://naif.jpl.nasa.gov/pub/naif/toolkit_docs/C/cspice/kxtrct_c.html
  
      :param keywd: Word that marks the beginning of text of interest.
      :type keywd: str
      :param terms: Set of words, any of which marks the end of text.
      :type terms: Array of str
      :param nterms: Number of terms.
      :type nterms: int
      :param instring: String containing a sequence of words.
      :type instring: str
      :param termlen: Length of strings in string array term.
      :type termlen: int
      :param stringlen: Available space in argument string.
      :type stringlen: int
      :param substrlen: Available space in output substring.
      :type substrlen: int
      :return:
              String containing a sequence of words,
              String from end of keywd to beginning of first terms item found.
      :rtype: tuple
      """
      assert nterms <= len(terms)
      # Python strings and string arrays => to C char pointers
      keywd = stypes.stringToCharP(keywd)
      terms = stypes.listToCharArrayPtr([s[:termlen-1] for s in terms[:nterms]],xLen=termlen,yLen=nterms)
      instring = stypes.stringToCharP(instring[:stringlen-1],inlen=stringlen)
      substr = stypes.stringToCharP(substrlen)
      # Python ints => to C ints
      termlen = ctypes.c_int(termlen)
      nterms = ctypes.c_int(nterms)
      stringlen = ctypes.c_int(stringlen)
      substrlen = ctypes.c_int(substrlen)
      found = ctypes.c_int()
      libspice.kxtrct_c(keywd, termlen, terms, nterms,
                        stringlen, substrlen, instring, ctypes.byref(found),
                        substr)
      return stypes.toPythonString(instring), stypes.toPythonString(
              substr), bool(found.value)